Transmission for engines



A. L. POWELL.

TRANSMISSION vFOR 'ENGINES. APucmou FILED DEC.8. 1920.

Patented July 12, 1921.

2 SHEETS-SHEET A. L. PQWELL.

TRANSMISSEON FOR- ENGINES.

APPLICATION man 050. 8. 1920.

1,384,343. Patented July 1;, 1921 2 SHEETS-SHEET 2,

Qjb I b) gwucnl'oz Application filed December 8, 1920. Serial No.

To all whom it may concern."

1 of Montana,

Be it known that l, ALvAI-I L. PownLL, a citizen of the United States, residing at Miles City, in the county of Custer and State have invented certain new and useful Improvements in. Transmission for Engines, of which the following a specific'ation.

My invention relates to improvements in t 1e transmitting member of engines, by which I secure a variation in the movement of the piston with reference to that of the crank, enabling me to gain ad vantages in the operation of such engines that are not possible with the constructions at present used. This applicationis for improvements shown over others contained in a series filed withit, bearing Serial Numbers 429,168, 429,170 to 42?,176, inclusive, but while the general principles are the same the construction here in described has uses and advantages of its own.

In this application I show a modification of my transmitting members, using cranks, suitably disposed, to replace the racks and pinions heretofore shown, but retaining the difierential relation between the stroke of the engine and that of the piston. In, the accompanying drawings* *igure 1 is an elevation ment, partly in section.

Fig; 2 is a similar view of a modification of the arrangement shown in Fig. 1.

Fig. 3 is a detail of the intermediate lever cranks.

Figs. 4 and 5 show a further modification of the originalv construction, the views being elevations from opposite points.

In F ig. 1 is shown a piston of any engine, but preferably of one of the internal "coni ustlon type, connected by a link, A the equivalenthereof the piston rod of an ordinary prime mover, to a crank at D, Figs. 1, 2 and 3. The crank D is centered on a shaft, D that is sup-ported at any con vcnicnt point, or by the engine frame. It will lie-noted in the views, Figs. 1 and 3, that I) is one of two cranks, the shorter of which, D is formed on the same crank member, the pair .ing integral, but differing in throw. To the crank D is attached a connecting rod, 13 that is fitted to a crank on an engine shaft. It is evident from this relation that on the outstroke of the piston A. the cranks and. D Flg. 1, will move in the direction of my improve Specification of Letters Patent.

Pa ten ted July 12, 1921.

of arrow; The stroke of D than that of I), the distance traveled by D will exceed that covered by D. On the return stroke of the piston the two cranks will move back to the point shown in Fig. l, working betweenthe loci a-i Assuming a piston stroke of six inches, the stroke of thesecondary crank D will travel approximately four inches, according to the scale of the drawing. The power developed in the long stroke of piston A will, therefore, be concentrated in the short stroke of the 4 It will be noted, however, that in Fig. l the center line of the piston does not coincide with the center line of the crank shaft. By this means the angularity of the piston rod, or link A is lessened in this form of construction.

he reciprocating action of the cranks is governed by the radius of the travel of t ese cranks, and the length of the piston stroke. In Fig. 2 I show an arrangementby which both the cranks, D,.D and the engine crank, all rotate in unison. This effect is secured by altering the radius of the crank circle a--b c-d, the radius bemg less than that of the radius arc a-b, in The piston stroke and crank stroke 1g. 1. in both'views, that is, in Fi 1 and 2, are

being greater similarly proportioned, the difference of length between piston and crank strokes being maintained.

11 Figs. 4 and 5 I show an arrangement of cranks by which I secure a balancing effect with reference to vibration. construction the intermediate crank D remains the same, but the secondary is multiplied, that is, D is balanced by another of equal throw, D, the two being set at one hundred and eighty degrees of the crank circle. The thrust of the piston is thus made to exert a double action on the engine crank shaft, the push of the crank D, being balanced by the pull of the crank D.

By the construction and arrangement shown I obtain a simple means of governing the I stroke, and the extra length of piston travel may be utilized in modifying the ordinary functions of a piston in an internal combustion engine. A partial vacuum toward end of stroke may be made to serve as a cooling means from the expansion derivable from along stroke greater thermal efficiency may be attained; or, the full poweroi the long stroke may be concentrated in a crank stroke relatively short. By a proper arrangement of valves the piston may be made to draw in a charge for a fraction of the length of 5 stroke. continuing and creating a partial vacuum that will effect a. cooling action on 7 engine walls and piston from the expansion of gases under such conditions, the lost work being returned on back stroke by the added 10 efi'ect of atmospheric or crank case pressure greater. At shorter intake and expansion-of charge through a greater length of stroke the speed will be lessened. Such an engine will have greaterinherent capacity for flexibility with reference to maximum and minimum loads than one of the ordinary type.

Various modifications of the arrangement shown in this application may be made without departing from my invention.

What I claim is new and ask to have pro- .tected by Letters Patent, is-

In a difierential transmission member, the combination of cranks ofdifi'erent pitch, supporting means for said cranks, a piston, a link from the crank of greater throw to said piston, a crank shaft, and a connecting rod irom the c 'ank of lesser throw to said crank shaft, for the purpose hereinbefore described. 3

In testimony whereof I aflix my -signature.

ALvAn L. POWELL. 

